Embosser element engraved with stepped sidewall and process for using same

Abstract

An embossing roll is disclosed herein. The embossing roll comprises a plurality of embossing protuberances that extend from a surface of the embossing roll. Each embossing protuberance includes a base portion adjacent to the surface of the embossing roll, a raised distal portion, and at least one sidewall connecting the base portion and the raised distal portion. The at least one sidewall comprises at least two steps. The stepped embossing protuberances may be used to increase caliper or softness of a tissue product. A method of embossing a tissue product is also disclosed herein. The method comprises feeding a tissue ply through a nip formed between the embossing roll as described herein and a counter roll in order to emboss the tissue ply according to a pattern of embossing protuberances located on the surface of the embossing roll.

Description

[0001] EMBOSSER ELEMENT ENGRAVED WITH STEPPED SIDEWALL AND PROCESS FOR USING SAME

[0002] CROSS-REFERENCE TO RELATED APPLICATION

[0003] The present application is related and has right of priority to U.S. Provisional Patent Application No. 63 / 737,193 filed on December 20, 2024, which is incorporated by reference in its entirety for all purposes.

[0004] BACKGROUND

[0005] Consumer tissue products such as facial tissue, bath tissue and paper wipers are generally used to absorb liquids and fluids. Such paper products are predominantly formed of cellulosic papermaking fibers by manufacturing techniques designed specifically to produce several important properties. For example, the products should have good bulk, a soft feel, and should be highly absorbent. Further, the products should also have a pleasant aesthetic appearance and should be resilient against deterioration in the environment in which they are used.

[0006] In the past, many attempts have been made to enhance certain physical properties of such products. For instance, to enhance the aesthetic appearance, a decorative paper product has been created by embossing a pattern onto one or both sides of the paper web during manufacturing. This standard mechanical embossing resulted in the deformation or breaking of fibers in an attempt to physically press the pattern into the web. Embossing patterns into tissue webs typically reduce the strength of the web.

[0007] In some embodiments, those skilled in the art have used embossing to increase the thickness of the tissue product, particularly bath tissue. For instance, embossing patterns have been used in order to increase the thickness of multi-ply products in order to improve softness, tactile feel, and roll bulk. Conventional embossing technologies, however, such as double embossed random lamination (DERL), double embosser synchronized lamination (DESL), or point-to-point embossing, have limits on the ability to generate volume at acceptable levels of basesheet degradation.

[0008] In other embodiments, the embossed patterns formed into a tissue product are not well defined and fade as the paper product is aged. For instance, uncreped, through-air dried tissue webs are not always amenable to receiving embossing patterns.

[0009] Some tissue webs, such as uncreped, through-air dried webs, have relatively high strength properties and using an embossing technique that actually causes strength degradation may be desired in order to increase softness or to improve the appearance of the embossed pattern. Controlling strength degradation while producing a visual pattern, however, has been challenging. In view of the above, a need currently exists for an embossing process in one aspect that is capable of not only creating decorative patterns into hard to emboss tissue webs, but that can also advantageously increase the softness of such webs.

[0010] SUMMARY

[0011] In general, the present disclosure is directed to a process for producing embossed tissue products having improved caliper, a soft feel, and various other properties. In one aspect, for instance, the process and system of the present disclosure can be used to dramatically enhance softness and / or the caliper of a tissue sheet with minimum strength degradation. In another aspect, the process and system of the present disclosure can be used to emboss a pattern into a tissue sheet that causes strength degradation and / or produces a visually appealing pattern that is distinct and does not fade over time. The present disclosure is also directed to tissue products made from the process.

[0012] In one example embodiment, the present disclosure is directed to an embossing roll for embossing nonwoven webs, such as tissue webs. The embossing roll includes a plurality of embossing protuberances that extend from a surface of the embossing roll. Each embossing protuberance includes a base portion adjacent the surface of the embossing roll and a raised distal portion.

[0013] Each embossing protuberance also includes at least one sidewall that connects the base portion and the raised distal portion, wherein the at least one sidewall comprises at least two steps. In certain embodiments, the at least two steps are formed by an engraving method, such as by direct laser engraving, chemical engraving, and / or mechanical engraving. In other example embodiments, the at least two steps may be formed by 3D printing.

[0014] In certain example embodiments, the at least two steps include from about 2 to about 15 steps, such as about 4 to about 10 steps. The at least two steps may be selectively engraved into the at least one sidewall to manipulate various properties of the embossed tissue product. For instance, in some example embodiments, the at least two steps cover the entire perimeter of the at least one sidewall. In other example embodiments, the at least two steps cover from about 90° to about 360° of the perimeter of the at least one sidewall, such as from about 180° to 270° of the perimeter of the at least one sidewall. The at least two steps may also be selectively engraved into the at least one sidewall depending on the direction in which a tissue web or product is produced. Thus, in some example embodiments, the at least two steps cover a portion of the at least one sidewall in a machinedirection, and in other example embodiments, a cross machine direction of the at least one sidewall is substantially free of the at least two steps. The embossing protuberances and their respective sidewalls and steps may have varying heights and widths. For instance, in one example embodiment, each embossing protuberance has a height that defines a distance from the base portion to the raised distal portion of about 0.5 mm to about 4 mm, such as from about 0.6 mm to about 3 mm, such as from about 0.7 mm to about 2 mm, such as from about 0.8 mm to about 1 .8 mm, such as from about 0.9 mm to about 1 .5 mm. In other example embodiments, the raised distal portion has a width or diameter (best fit) of about 0. 2 mm to about 2 mm, such as about 0.3 mm to about 1 . 5 mm, such as about 0.4 mm to about 0. 1 mm, such as about 0.5 mm to about 0.7 mm, and the base portion has a width of about 1 .0 mm to about 3.0 mm, such as about 1 15 mm to about 2 mm, such as about 1.17 mm to about 1.65 mm, such as about 1.23 mm to about 1.52 mm.

[0015] Each of the at least two steps include a landing and a riser. In certain example embodiments, the risers of the at least two steps have a height of about 0.05 mm to about 1 mm, such as from about 0.1 mm to about 0.75 mm, such as from about 0.25 to about 0.5 mm. In some example embodiments, the risers of the at least two steps have varying heights. In other example embodiments, the risers of the at least two steps have the same height. In other example embodiments, the landings of the at least two steps have a width of about 0.01 mm to about 0.15 mm, such as from about 0.025 mm to about 0.1 mm, such as from about 0.05 mm to about 0.075. In some example embodiments, the landings of the at least two steps have the same width. In other example embodiments, the landings of the at least two steps have varying widths. The at least two steps each comprise an edge where the landing and the riser connect.

[0016] In certain example embodiments, the at least one sidewall comprises 1 sidewall to 4 sidewalls. In some example embodiments, the at least one sidewall connecting the base portion and the raised distal portion is sloped upwards towards the raised distal portion at an angle of from about 20° to about 80°, such as from about 50° to about 70°, such as from about 55 ° to about 67.5 °.

[0017] The risers and the landings of the at least two steps may be selectively angled so as to improve desired physical characteristics of the embossed tissue products while also preventing fiber accumulation on the landings. Thus, in some example embodiments, the at least one sidewall that comprises the at least two steps includes at least a first riser that extends inwards towards the raised distal portion from the base portion to a first landing at an angle of about 90° to about 45°, such as about 80° to about 55°, such as from about 70° to about 60°. In other example embodiments, the at least one sidewall that comprises the at least two steps includes at least a second riser that extends inwards towards the distal portion from the first landing to a second landing at an angle of from about 90° to about 45°, such as about 80° to about 55°, such as from about 70° to about 60°. In certain example embodiments, the at least two steps further comprise one or more additional risers that extend inwards towards the distal portion from the second landing at an angle of from about 90° to about 45°, such as about 80° to about 55°, such as from about 70° to about 60°.Thus, in some example embodiments, the first landing, the second landing, or both are parallel with the base portion, and in other example embodiments the first landing, the second landing, or both are sloped upwards towards the raised distal portion.

[0018] The embossing roll includes a plurality of embossing protuberances, and in some embodiments, the embossing protuberances are micro-embossments. In some example embodiments, the surface of the embossing roll includes from about 5 embossing protuberances to about 80,000 embossing protuberances on average per 100 cm2of surface area, such as from about 100 embossing protuberances to about 20,000 embossing protuberances on average per 100 cm2of surface area, such as from about 300 embossing protuberances to about 10,000 embossing protuberances on average per 100 cm2of surface area.

[0019] The surface of the embossing roll may also include a pattern of embossing protuberances. For instance, in certain example embodiments, the embossing protuberances form spaced apart rows of line structures. In other example embodiments, the line structures are curvilinear or may have a wavelike pattern. In some example embodiments, the embossing protuberances are in a continuous pattern. In certain example embodiments, the embossing protuberances are in a non-continuous pattern.

[0020] The present disclosure is also directed to a process for embossing a tissue ply or sheet. The process can include feeding a tissue ply through a nip formed between the embossing roll as described above and a counter roll in order to emboss the tissue ply according to a pattern of embossing protuberances located on the surface of the embossing roll. In one embodiment, the process can be used to emboss a single ply tissue web for producing a single ply product. Alternatively, a tissue ply can be embossed and then attached to one or more tissue ply for creating a multi-ply product. The embossed tissue web can have a sheet bulk of from about 6 cc / g to about 20 cc / g, such as from about 10 cc / g to about 14 cc / g. Embossing a tissue web in accordance with the present disclosure can, in one aspect, dramatically increase the thickness of the tissue web. For instance, the tissue web can increase in caliper by greater than about 10%, such as greater than about 15%, such as greater than about 20%. The tissue product can have a basis weight of from about 14 gsm to about 80 gsm, such as from about 14 gsm to about 60 gsm, such as from about 14 gsm to about 30 gsm.

[0021] In one aspect, the tissue web emboss can be an uncreped through-air dried sheet for forming a single ply product. Alternatively, a multi-ply product can be formed in which at least one of the plies comprises a creped tissue web. The present disclosure is also directed to tissue products made according to the process described above. The tissue product of the present disclosure can be spirally wound into rolls with periodic lines of perforation for producing bath tissues and paper towels. Alternatively, the tissue product can be cut into individual sheets and marketed as interfolded stacks.

[0022] Other features and aspects of the present disclosure are discussed in greater detail below.

[0023] BRIEF DESCRIPTION OF THE DRAWINGS

[0024] A full and enabling disclosure of the present disclosure is set forth more particularly in the remainder of the specification, including reference to the accompanying figures, in which:

[0025] Figure 1 is a perspective view of one embodiment of an embossing roll made in accordance with the present disclosure;

[0026] Figure 2 is a perspective view of one embodiment of an embossing protuberance that form raised elements on the embossing roll illustrated in Figure 1 ;

[0027] Figure 3 is a perspective view of another embodiment of an embossing protuberance in accordance with the present disclosure;

[0028] Figure 4 is a perspective view of another embodiment of an embossing protuberance in accordance with the present disclosure;

[0029] Figure 5 is a partial cross-sectional view of another embodiment of an embossing protuberance in accordance with the present disclosure;

[0030] Figure 6 is a plan view of one embodiment of an embossing pattern that may be applied to the embossing roll illustrated in Figure 1 containing the embossing protuberances as shown in Figures 2-5;

[0031] Figure 7 is a cross-sectional view of one embodiment of an embossing process in accordance with the present disclosure;

[0032] Figure 8 is a cross-sectional view of another embodiment of an embossing process in accordance with the present disclosure;

[0033] Figure 9 is a perspective view of one embodiment of a spirally wound roll of tissue product made in accordance with the present disclosure;

[0034] Figure 10 is a perspective view of an interfolded stack of individual sheets of a tissue product made in accordance with the present disclosure; and

[0035] Figure 11 is a graphical representation of the results of the Example.

[0036] Repeat use of reference characters in the present specification and drawings is intended to represent the same or analogous features or elements of the present invention. DEFINITIONS

[0037] As used herein the term “machine direction” or “MD” generally refers to the direction in which a tissue web or product is produced. The term “cross-machine direction" or “CD” refers to the direction perpendicular to the machine direction.

[0038] As used herein the term “Fibrous Structure” refers to a structure comprising a plurality of elongated particulate having a length to diameter ratio greater than about 10 such as, for example, papermaking fibers and more particularly pulp fibers, including both wood and non-wood pulp fibers, and synthetic staple fibers. A non-limiting example of a fibrous structure is a tissue web comprising pulp fibers.

[0039] As used herein the term “Tissue Web" or “Tissue Ply" refers to a fibrous structure provided in sheet form and being suitable for forming a tissue product.

[0040] As used herein the term “Tissue Product” refers to products made from tissue webs and includes, bath tissues, facial tissues, paper towels, industrial wipers, foodservice wipers, napkins, medical pads, and other similar products. Tissue products may comprise one, two, three or more plies.

[0041] As used herein the term “Pattern” generally refers to the arrangement of one or more design elements. Within a given pattern the design elements may be the same or may be different, further the design elements may be the same relative size or may be different sizes. For example, in one embodiment, a single design element may be repeated in a pattern, but the size of the design element may be different from one design element to the next within the pattern.

[0042] As used herein, the term “Embossing Pattern or Design” generally refers to a decorative shape disposed across at least one dimension of a fibrous structure surface, the pattern may comprise a line element, discrete elements or other shapes. The embossing pattern comprises a portion of the fibrous structure lying out of plane with the surface plane of the fibrous structure. In general, the embossing pattern results from embossing the fibrous structure resulting in protrusions having a z- directional elevation on one side of the fibrous structure and raised areas on the opposite side of the fibrous structure.

[0043] As used herein the term “Line Structure” refers to an element, such as an embossing element, in the shape of a line, which may be continuous or discontinuous, such as discrete or interrupted. The line element may be of any suitable shape such as straight, bent, kinked, curled, curvilinear, serpentine, sinusoidal, and mixtures thereof that may form a regular or irregular, periodic or nonperiodic lattice work of structures wherein the line element exhibits a length along its path of at least 10 mm. In one example, the line element may comprise a plurality of discrete elements, such as dots and / or dashes for example, that are oriented together to form a line element. In certain embodiments, the line structure means an embossment or an embossing element that exhibits an aspect ratio of about 2:1 to about 5:1 , such as from about 3:1 to about 4:1.

[0044] As used herein the term “Continuous Embossment” or “Continuous Line Embossments” refers to an element, such as an embossing element, disposed on a fibrous structure that extends without interruption throughout one dimension of the fibrous structure.

[0045] As used herein the term “Discrete Elements or Shapes” refers to an element, such as an embossing element, disposed on a fibrous structure that does not extend continuously in any dimension of the fibrous structure.

[0046] As used herein the term “Basis Weight” (BW) generally refers to the bone dry weight per unit area of a tissue and is generally expressed as grams per square meter (gsm). Basis weight is measured using TAPPI test method T-220. While basis weight may be varied, tissue products prepared according to the present invention generally have a basis weight greater than about 10 gsm, such as from about 10 to about 150 gsm and more preferably from about 30 to about 60 gsm.

[0047] As used herein, the term “caliper” is the representative thickness of a single sheet (caliper of tissue products comprising two or more plies is the thickness of a single sheet of tissue product comprising all plies) measured in accordance with TAPPI test method T402 using a ProGage 500 Thickness Tester (Thwing-Albert Instrument Company, West Berlin, N.J.). The micrometer has an anvil diameter of 2.22 inches (56.4 mm) and an anvil pressure of 132 grams per square inch (per 6.45 square centimeters) (2.0 kPa).

[0048] As used herein the term “Sheet Bulk” refers to the quotient of the caliper (generally having units of pm) divided by the bone dry basis weight (generally having units of gsm). The resulting sheet bulk is expressed in cubic centimeters per gram (cc / g). While sheet bulk may vary depending on any one of a number of factors, tissue products prepared according to the present invention may have a sheet bulk greater than about 6.0 cc / g, such as greater than about 10.0 cc / g.

[0049] As used herein the term “dot embossment” or “dot emboss element” means an embossment or an embossing element that exhibits an aspect ratio of about 1 :1 to about 1 :1. In certain embodiments, the aspect ratio is about 1 :1 .25 or less, such as an aspect ratio from about 1 .0 to about 1 .25. Non-limiting examples of dot embossments are embossments having a circular, oval, square, or triangular cross-sectional shape.

[0050] DETAILED DESCRIPTION

[0051] It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only and is not intended as limiting the broader aspects of the present disclosure.

[0052] In general, the present disclosure is directed to an embossing process for tissue webs, an embossing roll and system for embossing tissue webs, and to tissue products made from the process. In one aspect, the embossing roll of the present disclosure can comprise a plurality of embossing protuberances. The plurality of embossing protuberances extend from a surface of the embossing roll, and each embossing protuberance includes a base portion adjacent to the surface of the embossing roll, a raised distal portion, and at least one sidewall connecting the base portion and the raised distal portion. The at least one sidewall comprises at least two steps, and in some example embodiments, may comprise about 2 to about 15 steps, such as about 4 to about 10 steps.

[0053] Without intending to be limited by theory, the present inventors believe that employing a “stepped” sidewall on the embossing protuberance with two or more steps may result in the ability to have a higher impact on the base sheet during the embossing process, which can provide many benefits to the resulting tissue product. For instance, the use of the stepped sidewalls on the embossing protuberance may result in a tissue product with increased caliper and enhanced aesthetic appearance, as the pattern created by the embossing protuberances may be more defined. Further, the present inventors believe that selectively controlling the placement of the at least two steps on the sidewall may also be able to achieve the above-mentioned benefits, while minimizing the strength degradation of the tissue.

[0054] Referring to FIG. 1 , for instance, one example embodiment of an embossing roll 26 made in accordance with the present disclosure illustrating a pattern 14 of embossing protuberances 18 is demonstrated An enlarged view of a single embossing protuberance is illustrated in FIG. 2-7.

[0055] As shown in FIG. 1 , the embossing protuberances 18 form a pattern 14 on a surface 28 of the embossing roll 26. The embossing protuberances 18, for instance, extend from the surface 28 of the embossing roll 26 and form raised embossing elements.

[0056] For instance, referring to FIG. 2-4, the embossing protuberances 18 have a base portion 16 that is attached to or is placed adjacent to the surface 28 of the embossing roll 26, a raised distal portion 20, and at least one sidewall 22 connecting the base portion 16 and the raised distal portion 20. The base portion 16 is spaced from a raised distal portion or top surface 20. The at least one sidewall 22 comprises at least two steps 24. In certain embodiments, the sidewall 22 may include 2 or more steps, such as 3 or more steps, such as 4 or more steps, such as 5 or more steps, such as 6 or more steps, such as 7 or more steps, such as 8 or more steps, such as 9 or more steps, such as 10 or more steps, such as 11 or more steps, such as 12 or more steps, such as 13 or more steps, such as 14 or more steps, and even such as 15 or more steps depending on the desired physical characteristics of the resulting tissue product. Thus, in some example embodiments, the sidewall 22 may include about 2 to about 15 steps, such as about 3 to about 12 steps, such as about 4 to about 10 steps.

[0057] Each of the at least two steps 24 include at least a landing 23 and a riser 25, wherein the at least two steps 24 each comprise an edge 27 where the landing 23 and the riser 25 connect. The risers 25 of the at least two steps 24 have a height of about 0.05 mm or greater, such as about 0. 075 mm or greater, such as about 0.1 mm or greater, such as about 0.25 mm or greater, such as about 0.35 mm or greater, and generally less than about 1 mm, such as less than about 0.75 mm, such as less than about 0.65 mm, such as less than about 0.6 mm, such as less than about 0.55 mm, such as less than about 0.5 mm. Thus, in some example embodiments, the risers 25 have a height of from about 0.05 mm to about 1 mm, such as from about 0.1 mm to about 0.75 mm, such as from about 0.25 to about 0.5 mm. In preferred example embodiments, the risers 25 of the at least two steps 24 have a height of about 0.1 mm to about 0.5 mm. In certain example embodiments, the risers 25 of the at least two steps 24 have the same height. In other example embodiments, the risers 25 of the at least two steps 24 may have varying heights. In some example embodiments, the height of the risers 25 may be modified so that a sidewall 22 may have various amounts of steps 24 with risers 25 that have a similar or the same height and other steps 24 with risers 25 that have varying heights.

[0058] Further, as demonstrated by FIGS. 2-4, the at least two steps 24 include a landing 23. The landings 23 of the at least two steps 24 have a width of about 0.01 mm or greater, such as about 0.025 mm or greater, such as about 0.050 mm or greater, and generally less than about 0.15 mm, such as less than about 0.1 mm, such as less than about 0.85 mm, such as less than about 0.75 mm. Thus, in some example embodiments, the landings 23 of the at least two steps 24 have a width of about 0.01 mm to about 0.15 mm, such as from about 0.025 mm to about 0.1 mm, such as from about 0.05 mm to about 0.075. In preferred example embodiments, the landings 23 of the at least two risers 24 have a width of about 0.025 mm to about 0.1 mm. In some example embodiments, the landings 23 of the at least two steps have the same width. Whereas, in other example embodiments, the landings 23 of the at least two steps 24 have varying widths. In some example embodiments, the width of the landings 23 may be modified so that a sidewall 22 may have various amounts of steps 24 with landings 23 that have a similar or the same width and other steps 24 with landings 23 that have varying widths.

[0059] Without intending to be limited by theory, the present inventors believe that modifying and selectively controlling the various heights and widths of the landings 23 and risers 25 may be able to target selected physical properties in the resulting tissue product. For instance, a sidewall 22 with more concentrated steps (i.e., shorter riser 25 heights and shorter landing 23 widths) may have an improved ability to increase the caliper of the resulting tissue product, whereas a sidewall 22 with less concentrated steps (i.e., larger riser 25 heights and larger landing 23 widths) may be able to also result in an increased caliper but may have better tensile degradation control. Further, in some example embodiments, steps 24 of different riser 25 heights and landing 23 widths may be concentrated in various portions of the sidewall to best control the desired physical properties of the resulting tissue product.

[0060] As demonstrated by FIGS. 2-3, the at least one sidewall 22 may include at least a first riser 32 that extends from the base portion 16 to a first landing 33 at an angle of about 90° or less, such as from about 85° or less, such as from about 80° or less, such as from about 75° or less, such as from about 70° or less, such as from about 65° or less, and generally greater than about 45°, such as greater than about 50°, such as greater than about 55°, such as greater than about 60°. In some example embodiments, the first riser 32 extends from the base portion 16 at an angle of from about 90° to about 45°, such as about 80° to about 55°, such as from about 70° to about 60°. It should be understood by one of ordinary skill in the art that if the center axis of the embossing protuberance 18 is at a 90° angle, the first riser 32 in some example embodiments may extend from an end of the base portion 16 to create an inverse “V” shape, such that the angle is 90° or less.

[0061] In certain example embodiments, the at least one sidewall 22 that comprises the at least two steps 24 includes at least a second riser 34 that extends inwards towards the raised distal portion 20 from the first landing 33 to a second landing 35 at an angle of from about 90° or less, such as from about 85° or less, such as from about 80° or less, such as from about 75° or less, such as from about 70° or less, such as from about 65° or less, and generally greater than about 45°, such as greater than about 50°, such as greater than about 55°, such as greater than about 60°. In some example embodiments, the second riser 34 extends inwards towards the raised distal portion 20 from the first landing 33 to a second landing 35 at an angle from about 90° to about 45°, such as from about 80° to about 55°, such as from about 70° to about 60°.

[0062] As demonstrated in FIG.3, in other example embodiments, the at least two steps 24 further comprise one or more additional landings 37, 39. In certain example embodiments, the at least two steps 24 include additional risers 36, 38 that extend inwards towards the raised distal portion 20 from the second landing 35 at an angle of from about 90° or less, such as from about 85° or less, such as from about 80° or less, such as from about 75° or less, such as from about 70° or less, such as from about 65° or less, and generally greater than about 45°, such as greater than about 50°, such as greater than about 55°, such as greater than about 60°. In preferred embodiments, the additional risers 36, 38 extend inwards towards the raised distal portion 20 at an angle of about 90° to about 45°, such as from about 80° to about 55°, such as from about 70° to about 60°.

[0063] Controlling the angle of the risers also will affect the position of the landings. For instance, in certain example embodiments, the landings of the at least two steps, including the first landing 33, the second landing 35, and / or additional landings 37, 39 are parallel with the base portion 16. In other example embodiments, the first landing 33, the second landing 35, and / or additional landings 37, 39 are sloped in relation to the base portion 16. For instance, in some example embodiments, landings may be sloped upwards towards the raised distal portion 20. In other example embodiments, as the landings may be sloped downwards towards the base portion 16.

[0064] The present inventors believe that selectively controlling the angles and slopes of the risers and landings may provide many advantages to the embossing protuberances 18. For instance, the present inventors believe that angling the risers and / or the landings inward on a slope towards the raised distal portion 20 allows for edges with a smaller vertical drop. Thus, controlling the angles of the risers and / or the landings may help reduce dust accumulation on flat areas, thereby increasing the ability of the embossing protuberances 18 to increase caliper and form sharp visual patterns in the resulting tissue product.

[0065] It should be understood by one of ordinary skill in the art that controlling the angles and slopes of the risers 25 and landings 23 may also affect the characteristics of the edge 27. However, the characteristics of the edge 27 may also be affected by various other factors, such as the strength and precision of the engraving techniques used to form the steps 24 and the material of the embossing roll. In certain example embodiments, the edge 27 of the at least two steps 24 is a sharp edge. In other example embodiments, the edge 27 of the at least two steps 24 is a rounded edge. The shape and / or sharpness of the edge may be selectively controlled based on the desired characteristics of the resulting tissue product. For instance, without intending to be limited by theory, a round edge may be utilized to prevent strength degradation, whereas a sharp edge may be utilized to improve the clarity and precision of the embossed designs. Further, in some example embodiments, a variety of embossing protuberances 18 with combinations of steps 24 with sharp and / or smooth edges may be utilized on a single embossing roll 26.

[0066] The at least two steps 24 may be formed on the at least one sidewall 22 by a variety of different means. Non-limiting examples of suitable processes include laser engraving hard plastic (e.g., ebonite) or ceramic or other material suitable for laser ablation to remove material and create the at least two steps 24, chemical engraving of steel or other materials to remove material and create the at least two steps 24, machining aluminum or steel or other metals to remove material and create the at least two steps 24, metallizing processes to build up the at least two steps 24, sintering processes to build up the at least two steps 24, 3D printing materials to build up the at least two steps 24, and / or other means known in the art to remove material or build up material and achieve a surface topography with the desired number of steps 24. Similar processes can also be used to generally form the embossing protuberances 18. In preferred embodiments, the at least two steps 24 in the at least one sidewall 22 are formed by laser engraving, such as direct laser engraving

[0067] For instance, in certain example embodiments, the at least two steps cover the entire perimeter of the at least one sidewall 22. In other example embodiments, the at least two steps 24 cover 90° or greater of the perimeter of the at least one sidewall 22, such as about 100° or greater, such as about 1 10° or greater, such as about 120° or greater, such as about 130° or greater, such as about 140° or greater, such as about 150° or greater, such as about 160° or greater, such as about 170° or greater, such as about 180° or greater, and generally less than about 360°, such a less than about 330°, such as less than about 300°, such as less than about 270°, such as less than about 250°, such as less than about 225°, such as less than about 200°. For instance, in some example embodiments, the at least two steps 24 cover from about 90° to about 360° of the perimeter of the at least one sidewall 24, such as from about 180° to 270° of the perimeter of the at least one sidewall 24.

[0068] As demonstrated by FIG. 5, the at least two steps 24 may also be selectively engraved into the at least one sidewall 22 depending on the direction in which a tissue web or product is produced. For instance, in certain example embodiments, the at least two steps 24 cover a portion of the sidewall 22 in a machine-direction 50. In other example embodiments, a cross machine direction 52 of the at least one sidewall 22 is substantially free of the at least two steps 24. The present inventors believe that utilizing the steps 24 on only the machine direction 50 helps preserve the strength of the resulting tissue product. However, it should be understood by one of ordinary skill in the art that any variation of step 24 placement may be utilized to impact the specific area of the tissue web of interest.

[0069] Referring now back to FIGS. 2-4, the at least one sidewall 22 connecting the base portion 16 and the raised distal portion 20 may be sloped upwards towards the raised distal portion 20 at an angle of from about 20° or greater, such as about 25° or greater, such as about 35° or greater, such as about 45° or greater, such as about 50° or greater, such as about 55° or greater, such as about 60° or greater, and generally less than about 80°, such as less than about 75°, such as less than about 70°, such as less than about 67.5°. Thus, in certain example embodiments, the at least one sidewall 22 is sloped upwards towards the raised distal portion 20 at an angle of from about 45° to about 80°, such as from about 50° to about 70°, such as from about 55 ° to about 67.5 °. It should be understood by one of ordinary skill in the art that if the center axis of the embossing protuberance 18 is at a 90° angle, the at least one sidewall 22 may generally slope upwards towards the raised distal portion 20 to form an inverse "V” shape such that the angle is 90° or less. Further, it should be understood that although the at least two steps 24 may have varying angles of their risers and landings, the overall sidewall may still be generally inward sloping. In certain example embodiments, the at least one sidewall comprises 1 sidewall to 6 sidewalls, such as 1 to 4 sidewalls. It should be understood by one of ordinary skill in the art that the number of sidewalls depends on the shape of the base portion 16, the raised distal portion 20, or both, as described below.

[0070] Each embossing protuberance 18 can have any suitable size and shape depending upon various factors including the characteristics of the tissue sheet being embossed, the type of tissue product being formed, the embossing pattern, and the like. In one aspect, each embossing protuberance 18 can comprise a discrete embossing element on the surface 28 of the embossing roll 26. In one example embodiment, each embossing protuberance 18 can comprise a dot embossment.

[0071] In certain example embodiments, each embossing protuberance 18 can have a height (distance from the base portion 16 to the distal portion 20) of greater than about 0.5 mm, such as greater than 0.6 mm, such as greater than about 0.7 mm, such as greater than about 0.8 mm, such as greater than about 0.9 mm, such as greater than about 1 .1 mm, such as greater than about 1 .3 mm, such as greater than about 1 5 mm, such as greater than about 1 7 mm, such as greater than about 2 mm. The height of the embossing protuberances 18 is generally less than about 5 mm, such as less than about 4 mm, such as less than about 3 mm, such as less than about 2 mm, such as less than about 1 .8 mm, such as less than about 1 .5 mm, such as less than about 1 .3 mm. In certain example embodiments, each embossing protuberance 18 has a height of about 0.5 mm to about 4 mm, such as from about 0.6 mm to about 3 mm, such as from about 0.7 mm to about 2 mm, such as from about 0.8 mm to about 1 .8 mm, such as from about 0.9 mm to about 1 .5 mm.

[0072] The raised distal portion 20 may have any suitable shape as known in the art, including, but not limited to, a rectangular shape, a circular shape, a square shape, an oblong shape, an ellipse shape, an oblique shape, a triangular shape, an irregular shape, and / or an oval shape. In certain example embodiments, the raised distal portion 20 has a width of about 0. 2 mm to about 2 mm , such as about 0.3 mm to about 1 . 5 mm, such as about 0.4 mm to about 1 mm, such as about 0.5 mm to about 0.7 mm.

[0073] When the raised distal portion 20 has a circular cross-sectional shape, the distal portion 20 can have a diameter (best fit) of generally greater than about 0.2 mm, such as greater than about 0.3 mm, such as greater than about 0.4 mm, such as greater than about 0.5 mm, and less than about 3 mm, such as less than about 2 mm, such as less than about 1 mm, such as less than about 0.9 mm, such as less than about 0.8 mm.

[0074] The area of the distal portion 20 of the embossing protuberances (whether circular or some other shape) can generally be less than about 7 mm2, such as less than about 4 mm2, such as less than about 3 mm2, such as less than about 2 mm2, such as less than about 1 mm2, such as less than about 0.8 mm2, such as less than about 0.7 mm2, such as less than about 0.6 mm2, such as less than about 0.5 mm2, such as less than about 0.4 mm2. The area of the distal portion of each embossing protuberance can generally be greater than about 0.01 mm2, such as greater than about 0.03 mm2, such as greater than about 0.05 mm2, such as greater than about 0.07 mm2, such as greater than about 0.09 mm2, such as greater than about 0.12 mm2, such as greater than about 0.15 mm2, such as greater than about 0.16 mm2, such as greater than about 0.17 mm2, such as greater than about 0.2 mm2.

[0075] Likewise, the base portion 16 may have any suitable shape as known in the art, including, but not limited to, a rectangular shape, a circular shape, a square shape, an oblong shape, an ellipse shape, an oblique shape, a triangular shape, an irregular shape, and / or an oval shape. In certain embodiments, the base portion 16 has a width of about 1.0 mm to about 3.0 mm, such as about 1.15 mm to about 2 mm, such as about 1.17 mm to about 1 .65 mm, such as about 1.23 mm to about 1.52 mm.

[0076] In this configuration, the embossing protuberances 18 and the embossing roll 26 are designed to create a visual embossing pattern into a tissue sheet while also decreasing strength, such as in the machine direction, for increasing the softness of the tissue sheet. This configuration, for instance, is particularly well suited for embossing hard to emboss tissue webs that traditionally have not been amenable to embossing processes in which the resulting embossing pattern is visually appealing. For instance, in this aspect, the tissue sheet being embossed can be a single ply uncreped through-air dried tissue sheet. Through the process of the present disclosure, an embossing pattern can be formed into the sheet that does not fade over time and that not only improves the visual appearance of the tissue sheet but also can dramatically improve softness. This configuration is also particularly well suited for embossing tissue sheets with higher basis weights, such as greater than about 35 gsm, such as greater than about 40 gsm, such as greater than about 45 gsm, such as greater than about 50 gsm, such as greater than about 55 gsm, and less than about 70 gsm.

[0077] The embossing roll 26 of the present disclosure is multi-functional, and in some example embodiments, may be in operative association with a heating device for heating the surface of the embossing roll 26. The embossing roll 26 including the embossing protuberances 18 of the present disclosure can, in one aspect, increase caliper without degrading strength or, alternatively, can decrease strength of a tissue sheet in a controlled way that improves softness.

[0078] The embossing protuberances 18 can form any suitable pattern on the embossing roll 26. The embossing roll 18 can include only the embossing protuberances or can include the embossing protuberances in combination with other embossing elements, such as decorative shapes. The embossing pattern, for instance, can include a high density of embossing protuberances 18 or can include a relatively low density of embossing protuberances 18 to form a pattern. The embossing protuberances 18 can uniformly cover the surface of the embossing roll as shown in FIG. 1. Alternatively, the embossing protuberances 18 can form spaced apart line structures as shown in FIG. 6. In one example embodiment, the embossing protuberances 18 can be present on the surface of the embossing roll 26 at a density of greater than about 5 embossing protuberances, such as greater than about 20 embossing protuberances, such as greater than about 50 embossing protuberances, such as greater than about 70 embossing protuberances, such as greater than about 100 embossing protuberances, such as greater than about 150 embossing protuberances, such as greater than about 200 embossing protuberances, such as greater than about 250 embossing protuberances, such as greater than about 300 embossing protuberances, such as greater than about 350 embossing protuberances, such as greater than about 400 embossing protuberances, such as greater than about 450 embossing protuberances, such as greater than about 500 embossing protuberances, such as greater than about 550 embossing protuberances, such as greater than about 600 embossing protuberances, such as greater than about 650 embossing protuberances, such as greater than about 700 embossing protuberances, such as greater than about 750 embossing protuberances, such as greater than about 800 embossing protuberances, such as greater than about 850 embossing protuberances, such as greater than about 900 embossing protuberances, such as greater than about 950 embossing protuberances, such as greater than about 1 ,000 embossing protuberances, such as greater than about 1 ,200 embossing protuberances, such as greater than about 1 ,500 embossing protuberances, such as greater than about 1 ,700 embossing protuberances, such as greater than about 2,000 embossing protuberances, such as greater than about 2,200 embossing protuberances, such as greater than about 2,500 embossing protuberances, such as greater than about 2,700 embossing protuberances, such as greater than about 3,000 embossing protuberances, such as greater than about 3,200 embossing protuberances, such as greater than about 3,500 embossing protuberances, such as greater than about 3,700 embossing protuberances, such as greater than about 4,000 embossing protuberances, such as greater than about 4,200 embossing protuberances, such as greater than about 4,500 embossing protuberances, such as greater than about 4,700 embossing protuberances, such as greater than about 5,000 embossing protuberances over an area of 100 cm2. The density of the embossing protuberances over an area of 100 cm2is generally less than about 15,000 embossing protuberances, such as less than about 12,000 embossing protuberances, such as less than about 10,000 embossing protuberances, such as less than about 8,000 embossing protuberances, such as less than about 6,000 embossing protuberances, such as less than about 5,000 embossing protuberances, such as less than about 4,000 embossing protuberances, such as less than about 3,000 embossing protuberances, such as less than about 2,000 embossing protuberances, such as less than about 1 ,000 embossing protuberances, such as less than about 900 embossing protuberances, such as less than about 800 embossing protuberances, such as less than about 700 embossing protuberances, such as less than about 600 embossing protuberances, such as less than about 500 embossing protuberances, such as less than about 400 embossing protuberances, such as less than about 300 embossing protuberances.

[0079] The pattern of the embossing protuberances 18 on the surface 28 of the embossing roll 26 can vary depending upon the particular application. In one embodiment, the embossing protuberances 18 can have a relatively high density and be uniformly spaced over the entire surface 28 of the embossing roll 26. Alternatively, the embossing protuberances 18 may form line structures on the surface 28 of the embossing roll 26. Each line structure can be spaced from an adjacent line structure. The line structures can be linear or curvilinear. In one embodiment, the line structures can have a wave-like shape.

[0080] For example, in FIG. 1 , the embossing protuberances 18 form an embossing pattern on the embossing roll 26. The embossing pattern comprises a continuous and regular pattern of dot embossments comprised of the embossing protuberances 18, which can be micro-embossments in one embodiment. For instance, the embossing protuberances can have an aspect ratio of from about 1 :1 to about 5:1 . In certain embodiments, when the embossing protuberances 18 are microembossments, the preferred aspect ratio is from about 1 to about 5, such as about 1 to about 4, such as about 1 to about 2, such as about 1 to about 1 .25, such as from about 1 to about 1 .1 . The embossing protuberances may be homogeneous in size and shape or can vary within a given pattern. In the embossing pattern shown in FIG. 1 , the embossing protuberances 18 are all of a single size. The embossing protuberances as shown in FIG. 1 are uniformly spaced apart and can display an embossment density of greater than about 1,000 embossing protuberances per 100 cm2, such as greater than about 2,000 embossing protuberances per 100 cm2, such as greater than about 2,500 embossing protuberances per 100 cm2, such as greater than 3,000 embossing protuberances per 100 cm2, such as greater than about 3,500 embossing protuberances per 100 cm2, such as greater than about 4,000 embossing protuberances per 100 cm2, such as greater than about 4,500 embossing protuberances per 100 cm2, such as greater than about 5,000 embossing protuberances per 100 cm2, and generally less than about 100,000 embossing protuberances per 100 cm2, such as less than about 80,000 embossing protuberances per 100 cm2, such as less than about 60,000 embossing protuberances per 100 cm2.

[0081] Referring now to FIG. 6, the embossing protuberances 18 comprise line structures that are discontinuous meaning that the line structures are made from discrete embossments or dot embossments. In this embodiment, the line structures are curvilinear and have a wave-like shape. Alternatively, however, the line structures can be linear. The line structures can extend in the crossdirection and can be spaced from one another such that they do not intersect. The embossing protuberances 18 can be spaced apart within each line structure (center point of distal portion to center point of distal portion of adjacent embossing protuberance) of greater than about 0.5 mm, such as greater than about 1 mm, such as greater than about 1.1 mm, such as greater than about 1 .2 mm, such as greater than about 1 .3 mm, such as greater than about 1 .4 mm, such as greater than about 1 .5 mm, and less than about 4 mm, such as less than about 3 mm, such as less than about 2 mm, such as less than about 1 .8 mm. The distance between each line structure can vary greatly depending upon the desired look or properties that are to be obtained. The line structures, for instance, can be spaced close together, can be spaced relatively far apart, or can include a combination of both as shown in FIG. 6. The line structures are generally spaced a distance of greater than about 1 mm apart, such as greater than about 1 .5 mm apart, such as greater than about 2 mm apart, such as greater than about 3 mm apart, such as greater than about 4 mm apart, such as greater than about 5 mm apart, such as greater than about 6 mm apart. Alternatively, the line structures can be spaced greater than about 15 mm apart, such as greater than about 20 mm apart, such as greater than about 30 mm apart. The line structures are generally spaced less than about 10,000 mm apart, such as less than about 1 ,000 mm apart.

[0082] The embossing roll can include a pattern of only discrete embossing elements as shown in FIG. 1. Alternatively, the embossing pattern can further include continuous line embossments. The line embossments can overlap with the pattern of the embossing protuberances 18. The continuous line embossments can be used to form decorative patterns or images into a tissue product. For instance, as shown in FIG. 6, the embossing pattern includes continuous line embossments 54 that are used to produce an image, such as a puppy. However, it should be understood that in some example embodiments, the embossing protuberances 18 may be placed in a discrete or non- continuous manner. In other embodiments, the embossing protuberances 18 may be utilized in various continuous or non-continuous schemes to selectively decrease the strength of the tissue product in select areas.

[0083] The embossing roll 26 as shown in FIG. 1 can be used to emboss all different types of sheet materials, particularly tissue webs. The embossing roll 26 can be used to emboss tissue webs for producing single ply products or multi-ply products. Referring to FIG. 7, for instance, one embodiment of a process for producing a multi-ply tissue product 10 is illustrated. As will be explained in greater detail below, in one aspect, a first tissue ply 12 is embossed in accordance with the present disclosure and then laminated to a second tissue ply 13. An adhesive or moisture can be used to attach the tissue plies together. The adhesive can be, for instance, a starch, a methylcellulose, or a polymer adhesive containing polypropylene, polyisobutylene, a polyurethane, a polyacrylate, a polyvinyl acetate, an ethylene vinyl acetate, or a polyvinyl alcohol.

[0084] As shown in FIG. 7, the first tissue ply 12 is conveyed past a series of idler rollers 122 towards a nip 124 that is located between an embossing roll 26 and a backing roll 128. Prior to entering the nip 124, in one aspect, the first tissue ply 12 can be prewetted with a prewetting solution such as water if desired.

[0085] The first tissue ply 12 is fed into the first nip 124 which can be a heated nip. The nip 124 is formed between the embossing roll 26 and a backing roll 128. The embossing roll 26 includes a pattern of male embossing protuberances 18 that embosses a pattern into the first tissue ply 12. During embossing, the tissue ply 12 can be heated.

[0086] The nip 124 can be heated using any suitable heating means. For instance, the embossing roll 26 can be heated, the backing roll 128 can be heated, or both rolls can be heated. In one aspect, the embossing roll 26 is heated. The nip 124 or the surface of the embossing roll 26, for instance, can be heated to a temperature of greater than about 70°C, such as greater than about 80°C, such as greater than about 90°C, such as greater than about 100°C, such as greater than about 110°C, such as greater than about 120°C, such as greater than about 130°C, such as greater than about 140°C, and less than about 220°C, such as less than about 200°C, such as less than about 190°C, such as less than about 180°C, such as less than about 170°C. In one aspect, the embossing roll 26 can be combined with a heating device that can be housed within the roll for heating by conduction. Alternatively, the embossing roll 26 can be heated by radiation and / or convection. As described above, the nip 124 formed between the embossing roll 26 and the backing roll 128 is heated for heating the tissue ply 12 as the tissue ply is embossed.

[0087] The embossing roll 26 is generally a hard and non-deformable roll. In particular embodiments, the embossing roll 26 is made of metal, especially steel, hard plastics materials, such as ebonite, or hard rubber. In case of plastics, very hard plastic material can be preferred, alternatively a resin material is also possible. In particular embodiments, the anvil roll is made of rubber like EPDM or NBR (acrylonitrile-butadiene rubber), paper or steel. The rubber can have a hardness between 20 and 85 Shore A, preferably between 50 and 75 Shore A.

[0088] The backing roll 128 can be a substantially smooth roll that, in one embodiment, can include a covering made of natural or synthetic rubber. The natural or synthetic rubber, for instance, can be polybutadiene or copolymers of ethylene and propylene or the like. In one aspect, the backing roll 128 has a hardness of greater than about 40 Shore A, such as from about 40 Shore A to about 100 Shore A including all increments of 1 Shore A therebetween. For example, in one aspect, the hardness of the backing roll 128 can be from about 50 Shore A to about 70 Shore A.

[0089] After the first tissue ply is embossed, it is laminated to one or more tissue ply, such as a second tissue ply, to form a multi-ply tissue product. Of course, it should be understood by one of ordinary skill in the art that the embossed tissue ply may form a three ply or four ply tissue product. The lamination process is carried out with or without the use of an adhesive.

[0090] A joining station may be configured such that the upper steel embossing roll abuts an aqueous or adhesive composition delivery assembly and a marrying roll to further laminate and join the first embossed ply to the second ply to form a multi-ply embossed tissue product according to the present disclosure. In particular, the upper steel embossing roll may abut an aqueous or adhesive composition delivery applicator which distributes a composition onto the embossed ply, particularly the protruding embossments of the embossed ply. After application of the composition, the embossed and wetted ply may be joined to the second ply by a marrying roll, which may be arranged such that it abuts the upper steel embossing roll. In this manner, the upper steel embossing roll and marrying roll may form a nip therebetween through which the plies pass and are joined together to form a multi-ply tissue product.

[0091] For instance, as shown in FIG. 7, the first tissue ply 12 enters the heated nip 124 and is embossed by the embossing roll 26 by the pattern of embossing elements or protuberances 18. Not only is the tissue ply 12 heated in the nip 124 but is also subjected to pressure against the embossing roll 26 for forming an embossing pattern into the tissue ply 12.

[0092] As shown, in order to form a two-ply tissue product, a second tissue ply 13 is conveyed and pressed into a nip 144 located between a substantially smooth roll 146 which may be made of rubber and a marrying roll 148, which may be a steel roll. The second tissue ply 13 can be adapted to form the bottom ply in the resulting multi-ply tissue product 10 or, alternatively, can be configured to be the top ply. As it is conveyed, the second tissue ply passes through the nip 144 where it is brought into contact with the first tissue ply 12, which now bears the embossing design as a result of being embossed by the embossing roll 26. The first and second plies 12 and 13 are joined together as they pass through the nip 144 to form a multi-ply tissue product 10.

[0093] As shown in FIG. 7, after the first tissue ply passes through the first nip 124 between the embossing roll 26 and the backing roll 128, a bonding unit 152 can apply a bonding solution to the distil ends of protrusions on the opposite surface of the first tissue ply 12 that is in contact with the embossing roll 26. For instance, as the tissue ply 12 is embossed on a first surface, protrusions form on the second surface according to the embossing pattern. In one aspect, the bonding unit 152 is positioned and configured only to apply a bonding solution to the top of the protrusions on the first tissue ply 12.

[0094] In one embodiment, the bonding unit 152 can include a distribution roll and a dosing roll. The bonding solution, which can comprise water or an adhesive is stored in a tank, is collected onto the distribution roll, and subsequently transferred to the dosing roll. The dosing roll contacts the protrusions on the first tissue ply 12 for applying the bonding solution to the tissue ply in a controlled manner.

[0095] It should be understood that the bonding unit 152 represents merely one way of applying the bonding solution to the first tissue ply 12. Various other techniques and methods can be used to apply the bonding solution to the first tissue ply 12. For instance, the bonding solution can be applied to the tissue ply using a gravure roll, through a digital printer, using a knife blade, or spraying the bonding solution onto the tissue ply 12.

[0096] In one aspect, the bonding solution is heated prior to being applied to the tissue ply 12. For instance, the bonding solution can be heated to a temperature of from about 60°C to about 90°C, including all increments of 1°C therebetween. For instance, the bonding solution can be heated to a temperature of greater than about 65°C, such as greater than about 70°C, such as greater than about 75°C, and less than about 85°C.

[0097] The bonding solution is generally applied to the first tissue ply 12 in an amount less than about 6% by weight, such as in an amount less than about 5% by weight, such as in an amount less than about 4% by weight, such as in an amount less than about 3% by weight, such as in an amount less than about 2% by weight, such as in an amount less than about 1% by weight. The bonding solution is applied to the first tissue ply 12 in an amount greater than about 0.1% by weight, such as in an amount greater than about 0.5% by weight, such as in an amount greater than about 1% by weight, such as in an amount greater than about 1 .5% by weight, such as in an amount greater than about 2% by weight.

[0098] As shown in FIG. 7, the embossed first tissue ply 12 with the applied bonding solution advances into the nip 144 and the second ply 13 is attached to the embossed first ply 12 to form the two-ply tissue product 10 which is subsequently spirally wound into a roll (not shown).

[0099] Through the above process, a tissue product 10 can be formed. The tissue product 10 can comprise a two-ply tissue product in which the first ply 12 is the embossed ply that forms the top of the product. The second ply 13, on the other hand, can be a non-embossed ply that remains relatively planar and forms the bottom surface of the product. Alternatively, the second ply 13 can be embossed similar to ply 12 or can be embossed, such as microembossed, with a conventional embossing pattern. In other embodiments, the tissue product 10 can include a third ply and / or a fourth ply.

[0100] Generally, the multi-ply products of the present disclosure are embossed and comprise two or more tissue plies bonded together along a plurality of bonded areas. In certain instances, the bonded areas may correspond to the embossments disposed on the one or more tissue plies. The embossed area, relative to the total area of the ply surface, and in-turn the bonded area, may range from about 2% to about 60%, such as from about 2% to about 30%, such as form about 2% to about 20%.

[0101] In addition to multi-ply tissue products, the embossing roll 26 of the present disclosure can also be used to produce single ply tissue products. For instance, as shown in FIG. 8, one embodiment of a process for embossing a tissue sheet and forming a single ply tissue product 10 is illustrated. As shown, a tissue ply is unwound, fed around guide rolls 122, and fed into a nip 124 created between the embossing roll 26 and a backing roll 128. The embossing roll 26 includes a pattern of embossing protuberances 18 in accordance with the present disclosure. The embossing protuberance 18 can have two more steps 24 as described above. The tissue sheet 12 is embossed within the nip 124 and / or in the nip 150 formed between the embossing roll 26 and a marrying roll 148. In this manner, a single ply tissue product 10 is formed that can include a distinctive and aesthetically pleasing embossing pattern. The embossing pattern can be used to improve one or more properties of the tissue sheet 12.

[0102] The embossing pattern, for instance, can increase the caliper of the tissue sheet 12. “Caliper” is the representative thickness of a single sheet. Alternatively, the embossing roll 26 can be used to degrade the strength of the tissue sheet 12 in a controlled manner that improves softness. In certain example embodiments, the embossed tissue ply increases in caliper by at least about 10%, such as by at least about 15%, such as by at least about 20%, such as by at least about 25%, such as by at least about 30%, such as by at least about 35%, such as by at least about 40%, such as by at least about 45%, such as by at least about 50%. Thus, in other example embodiments, the embossed tissue ply increases in caliper from about 10% to about 50%, such as by about 15% to about 45%, such as by about 20% to about 40%.

[0103] In certain example embodiments, embossed tissue ply made from embossing rolls with the stepped embossing protuberances as described herein may be about 10 pm thicker than an embossed tissue ply made with un-stepped or “smooth” embossing protuberances, such as about 15 m thicker, such as about 20 pm thicker, such as about 25 pm thicker, such as about 30 pm thicker, such as about 35 pm thicker, such as about 40 pm thicker, and generally less than 70 pm thicker, such as less than about 60 pm thicker, such as less than about 50 pm thicker, such as less than about 45 pm thicker. In other example embodiments, the embossed tissue ply made from the embossing rolls with the stepped embossing protuberances disclosed herein may be about 20 pm to about 60 pm thicker than an embossed tissue ply made with un-stepped or “smooth” embossing protuberances, such as about 25 pm to about 50 pm thicker, such as about 30 pm to about 40 pm thicker.

[0104] In general, any suitable tissue ply can be embossed in accordance with the present disclosure. The tissue ply, for instance, can comprise any suitable nonwoven material that can be made through a wetlaid process, air-laying, or through a foam forming process. The tissue ply generally contains cellulose fibers, particularly cellulose pulp fibers. For instance, the tissue ply can contain greater than about 40% by weight, such as greater than about 50% by weight, such as greater than about 60% by weight, such as greater than about 70% by weight cellulose pulp fibers. The multiply products in accordance with the present disclosure can be used to produce numerous products including bath tissue, facial tissue, table napkins, paper towels, and the like. The tissue product can contain a single tissue ply or at least two tissue plies, such as three tissue plies or four tissue plies.

[0105] The embossed tissue products of the present invention generally have a total product basis weight of at least about 14 gsm, such as at least about 20 gsm, such as at least about 30 gsm, such as at least about 35 gsm, such as at least about 40 gsm, such as at least about 45 gsm and less than about 75 gsm. In certain instances, the product basis weight may range from about 14 gsm to about 70 gsm, such as from about 20 gsm to about 65 gsm, such as about 30 gsm to about 60 gsm. Single ply tissue products made according to the present disclosure can generally have a basis weight of from about 14 gsm to about 35 gsm, while multi-ply tissue products can have a basis weight of from about 20 gsm to about 70 gsm. The basis weight of one tissue ply is generally greater than about 14 gsm, such as greater than about 18 gsm, such as greater than about 22 gsm, such as greater than about 26 gsm, and less than about 40 gsm, such as less than about 35 gsm, such as less than about 30 gsm.

[0106] In general, any suitable tissue web can be embossed in accordance with the present disclosure and incorporated into the tissue product 10. Bath tissue, facial tissue, paper towels, industrial wipers, and the like can be formed in accordance with the present disclosure. The tissue product 10 can be packaged as individual sheets contained in a dispenser or can be offered to consumers in the form of a spirally wound roll. Tissue products and the tissue plies incorporated into the product can generally have a bulk density of greater than about 3 cc / g, such as greater than about 5 cc / g, such as greater than about 6 cc / g, such as greater than about 7 cc / g, such as greater than about 8 cc / g, such as greater than about 9 cc / g, such as greater than about 10 cc / g, such as greater than about 11 cc / g, such as greater than about 12 cc / g, and generally less than about 20 cc / g.

[0107] Fibers suitable for making tissue webs comprise any natural or synthetic cellulosic fibers including, but not limited to nonwoody fibers, such as cotton, abaca, kenaf, sabai grass, flax, esparto grass, straw, jute hemp, bagasse, milkweed floss fibers, and pineapple leaf fibers; and woody or pulp fibers such as those obtained from deciduous and coniferous trees, including softwood fibers, such as northern and southern softwood kraft fibers; hardwood fibers, such as eucalyptus, maple, birch, and aspen. Pulp fibers can be prepared in high-yield or low-yield forms and can be pulped in any known method, including kraft, sulfite, high-yield pulping methods and other known pulping methods. Fibers prepared from organosolv pulping methods can also be used, including the fibers and methods disclosed in U.S. Pat. No. 4,793,898, issued Dec. 27, 1988 to Laamanen et al.; U.S. Pat. No. 4,594,130, issued Jun. 10, 1986 to Chang et al.; and U.S. Pat. No. 3,585,104. Useful fibers can also be produced by anthraquinone pulping, exemplified by U.S. Pat. No. 5,595,628 issued Jan. 21 , 1997, to Gordon et al.

[0108] A portion of the fibers, such as up to 50% or less by dry weight, or from about 5% to about 30% by dry weight, can be synthetic fibers such as rayon, polyolefin fibers, polyester fibers, bicomponent sheath-core fibers, multi-component binder fibers, and the like. An exemplary polyethylene fiber is Pulpex®, available from Hercules, Inc. (Wilmington, Del.). Any known bleaching method can be used. Synthetic cellulose fiber types include rayon in all its varieties and other fibers derived from viscose or chemically-modified cellulose.

[0109] Chemically treated natural cellulosic fibers can be used such as mercerized pulps, chemically stiffened or crosslinked fibers, or sulfonated fibers. For good mechanical properties in using papermaking fibers, it can be desirable that the fibers be relatively undamaged and largely unrefined or only lightly refined. While recycled fibers can be used, virgin fibers are generally useful for their mechanical properties and lack of contaminants. Mercerized fibers, regenerated cellulosic fibers, cellulose produced by microbes, rayon, and other cellulosic material or cellulosic derivatives can be used. Suitable papermaking fibers can also include recycled fibers, virgin fibers, or mixes thereof. In certain embodiments capable of high bulk and good compressive properties, the fibers can have a Canadian Standard Freeness of at least 200, more specifically at least 300, more specifically still at least 400, and most specifically at least 500.

[0110] Other papermaking fibers that can be used in the present disclosure include paper broke or recycled fibers and high yield fibers. High yield pulp fibers are those papermaking fibers produced by pulping processes providing a yield of about 65% or greater, more specifically about 75% or greater, and still more specifically about 75% to about 95%. Yield is the resulting amount of processed fibers expressed as a percentage of the initial wood mass. Such pulping processes include bleached chemithermomechanical pulp (BCTMP), chemithermomechanical pulp (CTMP), pressure / pressure thermomechanical pulp (PTMP), thermomechanical pulp (TMP), thermomechanical chemical pulp (TMCP), high yield sulfite pulps, and high yield Kraft pulps, all of which leave the resulting fibers with high levels of lignin. High yield fibers are well known for their stiffness in both dry and wet states relative to typical chemically pulped fibers.

[0111] In general, any process capable of forming a paper web can also be utilized in the present disclosure. For example, a papermaking process of the present disclosure can utilize creping, wet creping, double creping, embossing, wet pressing, air pressing, through-air drying, creped through-air drying, uncreped through-air drying, hydroentangling, air laying, as well as other steps known in the art. The tissue web may be formed from a fiber furnish containing pulp fibers in an amount of at least about 50% by weight, such as at least about 60% by weight, such as at least about 70% by weight, such as at least about 80% by weight, such as at least about 90% by weight, such as 100% by weight.

[0112] The tissue web can also be formed without a substantial amount of inner fiber-to-fiber bond strength. In this regard, the fiber furnish used to form the base web can be treated with a chemical debonding agent. The debonding agent can be added to the fiber slurry during the pulping process or can be added directly to the headbox. Suitable debonding agents that may be used in the present disclosure include cationic debonding agents such as fatty dialkyl quaternary amine salts, mono fatty alkyl tertiary amine salts, primary amine salts, imidazoline quaternary salts, silicone quaternary salt and unsaturated fatty alkyl amine salts. Other suitable debonding agents are disclosed in U.S. Pat. No. 5,529,665 to Kaun which is incorporated herein by reference. In particular, Kaun discloses the use of cationic silicone compositions as debonding agents.

[0113] In one embodiment, the debonding agent used in the process of the present disclosure is an organic quaternary ammonium chloride and, particularly, a silicone-based amine salt of a quaternary ammonium chloride. For example, the debonding agent can be PROSOFT® TQ1003, marketed by the Hercules Corporation. The debonding agent can be added to the fiber slurry in an amount of from about 1 kg per metric tonne to about 10 kg per metric tonne of fibers present within the slurry.

[0114] In an alternative embodiment, the debonding agent can be an imidazoline-based agent. The imidazoline-based debonding agent can be obtained, for instance, from the Witco Corporation. The imidazoline-based debonding agent can be added in an amount of between 2.0 to about 15 kg per metric tonne.

[0115] In one embodiment, the debonding agent can be added to the fiber furnish according to a process as disclosed in PCT Application having an International Publication No. WO 99 / 34057 filed on Dec. 17, 1998 or in PCT Published Application having an International Publication No. WO 00 / 66835 filed on Apr. 28, 2000, which are both incorporated herein by reference. In the above publications, a process is disclosed in which a chemical additive, such as a debonding agent, is adsorbed onto cellulosic papermaking fibers at high levels. The process includes the steps of treating a fiber slurry with an excess of the chemical additive, allowing sufficient residence time for adsorption to occur, filtering the slurry to remove unadsorbed chemical additives, and redispersing the filtered pulp with fresh water prior to forming a nonwoven web.

[0116] Optional chemical additives may also be added to the aqueous papermaking furnish or to the formed embryonic web to impart additional benefits to the product and process and are not antagonistic to the intended benefits of the invention. The following materials are included as examples of additional chemicals that may be applied to the web along with the additive composition of the present invention. The chemicals are included as examples and are not intended to limit the scope of the invention. Such chemicals may be added at any point in the papermaking process, including being added simultaneously with the additive composition in the pulp making process, wherein said additive or additives are blended directly with the additive composition.

[0117] Additional types of chemicals that may be added to the paper web include, but is not limited to, absorbency aids usually in the form of cationic, anionic, or non-ionic surfactants, humectants and plasticizers such as low molecular weight polyethylene glycols and polyhydroxy compounds such as glycerin and propylene glycol. Materials that supply skin health benefits such as mineral oil, aloe extract, vitamin e, silicone, lotions in general and the like may also be incorporated into the finished products.

[0118] In general, the products of the present invention can be used in conjunction with any known materials and chemicals that are not antagonistic to its intended use. Examples of such materials include but are not limited to odor control agents, such as odor absorbents, activated carbon fibers and particles, baby powder, baking soda, chelating agents, zeolites, perfumes or other odor-masking agents, cyclodextrin compounds, oxidizers, and the like. Superabsorbent particles, synthetic fibers, or films may also be employed. Additional options include cationic dyes, optical brighteners, humectants, emollients, and the like.

[0119] Tissue webs that may be treated in accordance with the present disclosure may include a single homogenous layer of fibers or may include a stratified or layered construction. For instance, the tissue web ply may include two or three layers of fibers.

[0120] Tissue webs that can be embossed in accordance with the present disclosure can be formed using any suitable process. The tissue webs can comprise wetlaid or foam-formed tissue webs. The tissue webs can be formed using creped wet pressed, modified wet pressed, creped through-air dried, or uncreped through-air dried. In one embodiment, an embryonic tissue web is transferred to a Yankee dryer, which completes the drying process, and then is creped from the surface of the dryer using a doctor blade or other suitable device.

[0121] In other instances, the tissue plies may be manufactured by a through-air dried process known in the art. In such processes the embryonic web is noncompressively dried. For example, textured tissue plies may be formed by either creped or uncreped through-air dried processes. Particularly preferred are uncreped through-air dried webs, such as those described in U.S. Pat. No. 5,779,860, the contents of which are incorporated herein in a manner consistent with the present disclosure.

[0122] In still other instances the tissue plies may be manufactured by a process including the step of using pressure, vacuum, or air flow through the wet web (or a combination of these) to conform the wet web into a shaped fabric and subsequently drying the shaped sheet using a Yankee dryer, or series of steam heated dryers, or some other means, including but not limited to tissue made using the ATMOS process developed by Voith or the NTT process developed by Metso; or fabric creped tissue, made using a process including the step of transferring the wet web from a carrying surface (belt, fabric, felt, or roll) moving at one speed to a fabric moving at a slower speed (at least 5 percent slower) and subsequently drying the sheet. Those skilled in the art will recognize that these processes are not mutually exclusive, e.g., an uncreped TAD process may include a fabric crepe step in the process.

[0123] The tissue product may be constructed from two or more plies that are manufactured using the same or different tissue making techniques. In a particularly preferred embodiment, the multi-ply tissue product comprises two or three plies wherein at least one of the plies is a through-air dried ply.

[0124] The basis weight of tissue webs made in accordance with the present disclosure can vary depending upon the final product. For example, the process may be used to produce bath tissues, facial tissues, paper towels, industrial wipers, and the like. In general, the basis weight of the tissue products may vary from about 10 gsm to about 110 gsm, such as from about 20 gsm to about 90 gsm. For bath tissue and facial tissues, for instance, the basis weight may range from about 10 gsm to about 40 gsm. For paper towels, on the other hand, the basis weight may range from about 25 gsm to about 80 gsm.

[0125] In multiple ply products, the basis weight of each tissue web present in the product can also vary. In general, the total basis weight of a multiple ply product will generally be the same as indicated above, such as from about 20 gsm to about 110 gsm. Thus, the basis weight of each ply can be from about 10 gsm to about 60 gsm, such as from about 20 gsm to about 40 gsm.

[0126] All different types of products can be made in accordance with the present disclosure. For instance, in one embodiment, the tissue product 10 of the present disclosure can be used to produce a spirally wound roll 200 as shown in FIG. 9. The spirally wound roll 200, for instance, can comprise a bath tissue. As shown, the tissue product 10 includes an embossing pattern 12. The spirally wound roll of the tissue product 10 can be periodically perforated for allowing a user to tear off individual sheets.

[0127] In an alternative embodiment, the tissue product 10 can be formed into a spirally wound roll that comprises a paper towel or industrial wiper.

[0128] In still another embodiment, the tissue product 10 of the present disclosure can be cut into individual sheets and formed into a stack 300 as shown in FIG. 10. The stack of individual sheets 300 can be interfolded if desired. In one embodiment, the stack of individual sheets 300 can comprise a facial tissue product. EXAMPLE

[0129] Two sets of Light Dry Crepe (LDC) basesheets having a basis weight of 19.5 gsm, caliper of 1450 m per 12 plies, and bulk of 6.1 cc / g were embossed according to Table 1 . As shown, the control set utilized existing micro embossing of 60 embossing protuberances per cm2, the embossing protuberances having at least one sidewall that is “smooth,” such that it has one or less steps. Conversely, Sample 1 utilized stepped embossing protuberances as disclosed herein. Namely, Sample 1 also utilized 60 embossments per cm2, the embossing protuberances having at least one sidewall with two or more steps (as illustrated in FIGS. 2-5). The samples were tested for caliper, as shown in FIG. 11.

[0130] As demonstrated by FIG. 11 , the samples according to the present disclosure exhibited an increase in caliper of about 30 pm to about 40 pm compared to the control.

[0131] These and other modifications and variations to the present invention may be practiced by those of ordinary skill in the art, without departing from the spirit and scope of the present invention, which is more particularly set forth in the appended claims. In addition, it should be understood that aspects of the various embodiments may be interchanged both in whole or in part. Furthermore, those of ordinary skill in the art will appreciate that the foregoing description is by way of example only and is not intended to limit the invention so further described in such appended claims.

[0132] EXAMPLE EMBODIMENTS

[0133] Example Embodiment 1 : An embossing roll comprising: a plurality of embossing protuberances that extend from a surface of the embossing roll, each embossing protuberance including a base portion adjacent to the surface of the embossing roll, a raised distal portion, and at least one sidewall connecting the base portion and the raised distal portion, wherein the at least one sidewall comprises at least two steps.

[0134] Example Embodiment 2: The embossing roll of example embodiment 1 , wherein the at least two steps comprise about 2 to about 15 steps, such as about 4 to about 10 steps. Example Embodiment 3: The embossing roll as in any preceding embodiment, wherein the at least two steps cover from about 90° to about 360° of the perimeter of the at least one sidewall, such as from about 180° to 270° of the perimeter of the at least one sidewall.

[0135] Example Embodiment 4: The embossing roll as in any preceding embodiment, wherein each embossing protuberance has a height that defines a distance from the base portion to the raised distal portion of about 0.5 mm to about 4 mm, such as from about 0.6 mm to about 3 mm, such as from about 0.7 mm to about 2 mm, such as from about 0.8 mm to about 1 .8 mm, such as from about 0.9 mm to about 1.5 mm.

[0136] Example Embodiment 5: The embossing roll as in any preceding embodiment, wherein the raised distal portion has a width of about 0. 2 mm to about 2 mm, such as about 0.3 mm to about 1 . 5 mm, such as about 0.4 mm to about 0. 1 mm, such as about 0.5 mm to about 0.7 mm.

[0137] Example Embodiment 6: The embossing roll as in any preceding embodiment, wherein the base portion has a width of about! .0 mm to about 3.0 mm, such as about 1.15 mm to about 2 mm, such as about 1 .17 mm to about 1 .65 mm, such as about 1 .23 mm to about 1 .52 mm.

[0138] Example Embodiment 7 : The embossing roll as in any preceding embodiment, wherein the at least two steps comprise a landing and a riser, wherein the at least two steps each comprise an edge where the landing and the riser connect.

[0139] Example Embodiment 8: The embossing roll as in any preceding embodiment, wherein the risers of the at least two steps have a height of about 0.05 mm to about 1 mm, such as from about 0.1 mm to about 0.75 mm, such as from about 0.25 to about 0.5 mm.

[0140] Example Embodiment 9: The embossing roll as in any preceding embodiment, wherein the landings of the at least two steps have a width of about 0.01 mm to about 0.15 mm, such as from about 0.025 mm to about 0.1 mm, such as from about 0.05 mm to about 0.075.

[0141] Example Embodiment 10: The embossing roll as in any preceding embodiment, wherein the risers of the at least two steps have varying heights. Example Embodiment 11 : The embossing roll as in any preceding embodiment, wherein the landings of the at least two steps have varying widths.

[0142] Example Embodiment 12: The embossing roll as in any preceding embodiment, wherein the at least one sidewall that comprises the at least two steps includes at least a first riser that extends inwards towards the raised distal portion from the base portion to a first landing at an angle of about 90° to about 45°, such as about 80° to about 55°, such as from about 70° to about 60°.

[0143] Example Embodiment 13: The embossing roll as in any preceding embodiment, wherein the at least one sidewall that comprises the at least two steps includes at least a second riser that extends inwards towards the raised distal portion from the first landing to a second landing at an angle of from about 90° to about 45°, such as about 80° to about 55°, such as from about 70° to about 60°.

[0144] Example Embodiment 14: The embossing roll as in any preceding embodiment, wherein the first landing, the second landing, or both are parallel with the base portion.

[0145] Example Embodiment 15: The embossing roll as in any preceding embodiment, wherein the first landing, the second landing, or both are sloped upwards towards the raised distal portion.

[0146] Example Embodiment 16: The embossing roll as in any preceding embodiment, wherein the at least two steps further comprise one or more additional risers that extend inwards towards the raised distal portion from the second landing at an angle of from about 90° to about 45°, such as about 80° to about 55°, such as from about 70° to about 60°.

[0147] Example Embodiment 17: The embossing roll as in any preceding embodiment, wherein the at least one sidewall connecting the base portion and the raised distal portion is sloped upwards towards the raised distal portion at an angle of from about 20° to about 80°, such as from about 50° to about 70°, such as from about 55 ° to about 67.5 °.

[0148] Example Embodiment 18: The embossing roll as in any preceding embodiment, wherein the at least two steps cover a portion of the at least one sidewall in a machine-direction.

[0149] Example Embodiment 19: The embossing roll as in any preceding embodiment, wherein a cross machine direction of the at least one sidewall is substantially free of the at least two steps. Example Embodiment 20: The embossing roll as in any preceding embodiment, wherein the surface of the embossing roll includes a pattern of embossing protuberances.

[0150] Example Embodiment 21 : The embossing roll as in any preceding embodiment, wherein the surface of the embossing roll includes from about 5 embossing protuberances to about 80,000 embossing protuberances on average per 100 cm2of surface area, such as from about 100 embossing protuberances to about 20,000 embossing protuberances on average per 100 cm2of surface area, such as from about 300 embossing protuberances to about 10,000 embossing protuberances on average per 100 cm2of surface area.

[0151] Example Embodiment 22: The embossing roll as in any preceding embodiment, wherein the embossing protuberances are micro-embossments.

[0152] Example Embodiment 23: The embossing roll as in any preceding embodiment, wherein the embossing protuberances form spaced apart rows of line structures.

[0153] Example Embodiment 24: The embossing roll as in any preceding embodiment, wherein the embossing protuberances are in a continuous pattern.

[0154] Example Embodiment 25: The embossing roll as in any preceding embodiment, wherein the embossing protuberances are in a non-continuous pattern.

[0155] Example Embodiment 26: A method of embossing a tissue product comprising: feeding a tissue ply through a nip formed between the embossing roll as defined in any preceding embodiment and a counter roll in order to emboss the tissue ply according to a pattern of embossing protuberances located on the surface of the embossing roll

[0156] Example Embodiment 27: The method as described example embodiment 26, wherein the process produces a single ply tissue product.

[0157] Example Embodiment 28: The method as described in any preceding embodiment, wherein the embossed tissue ply is attached to one or more tissue ply for producing a multi-ply tissue product. Example Embodiment 29: The method as described in any preceding embodiment, wherein the embossed tissue ply increases in caliper by at least about 10%, such as by at least about 15%, such as by at least about 20%, such as by at least about 25%, such as by at least about 30%, such as by at least about 35%, such as by at least about 40%, such as by at least about 45%, such as by at least about 50%.

Claims

What Is Claimed:1 . An embossing roll comprising: a plurality of embossing protuberances that extend from a surface of the embossing roll, each embossing protuberance including a base portion adjacent to the surface of the embossing roll, a raised distal portion, and at least one sidewall connecting the base portion and the raised distal portion, wherein the at least one sidewall comprises at least two steps.

2. The embossing roll of claim 1 , wherein the at least two steps comprise about 2 to about 15 steps, such as about 4 to about 10 steps.3 The embossing roll of claim 1 , wherein the at least two steps cover from about 90° to about 360° of the perimeter of the at least one sidewall, such as from about 180° to 270° of the perimeter of the at least one sidewall.

4. The embossing roll of claim 1 , wherein each embossing protuberance has a height that defines a distance from the base portion to the raised distal portion of about 0.5 mm to about 4 mm, such as from about 0.6 mm to about 3 mm, such as from about 0.7 mm to about 2 mm, such as from about 0.8 mm to about 1 .8 mm, such as from about 0.9 mm to about 1 .5 mm.

5. The embossing roll of claim 1 , wherein the raised distal portion has a width of about 0.2 mm to about 2 mm, such as about 0.3 mm to about 1 . 5 mm, such as about 0.4 mm to about 0. 1 mm, such as about 0.5 mm to about 0.7 mm.

6. The embossing roll of claim 1 , wherein the base portion has a width of about 1 .0 mm to about 3.0 mm, such as about 1.15 mm to about 2 mm, such as about 1.17 mm to about 1.65 mm, such as about 1 .23 mm to about 1 .52 mm.

7. The embossing roll of claim 1 , wherein the at least two steps comprise a landing and a riser, wherein the at least two steps each comprise an edge where the landing and the riser connect.

8. The embossing roll of claim 7, wherein the risers of the at least two steps have a height of about 0.05 mm to about 1 mm, such as from about 0.1 mm to about 0.75 mm, such as from about 0.25 to about 0.5 mm.9 The embossing roll of claim 7, wherein the landings of the at least two steps have a width of about 0.01 mm to about 0.15 mm, such as from about 0.025 mm to about 0.1 mm, such as from about 0.05 mm to about 0.075.

10. The embossing roll of claim 7, wherein the risers of the at least two steps have varying heights.11 . The embossing roll of claim 7, wherein the landings of the at least two steps have varying widths.

12. The embossing roll of claim 1 , wherein the at least one sidewall that comprises the at least two steps includes at least a first riser that extends inwards towards the raised distal portion from the base portion to a first landing at an angle of about 90° to about 45°, such as about 80° to about 55°, such as from about 70° to about 60°.

13. The embossing roll of claim 12, wherein the at least one sidewall that comprises the at least two steps includes at least a second riser that extends inwards towards the raised distal portion from the first landing to a second landing at an angle of from about 90° to about 45°, such as about 80° to about 55°, such as from about 70° to about 60°.

14. The embossing roll of claim 13, wherein the first landing, the second landing, or both are parallel with the base portion.

15. The embossing roll of claim 13, wherein the first landing, the second landing, or both are sloped upwards towards the raised distal portion.

16. The embossing roll of claim 13, wherein the at least two steps further comprise one or more additional risers that extend inwards towards the raised distal portion from the second landing at an angle of from about 90° to about 45°, such as about 80° to about 55°, such as from about 70° to about 60°.

17. The embossing roll of claim 1 , wherein the at least one sidewall connecting the base portion and the raised distal portion is sloped upwards towards the raised distal portion at an angle of from about 20° to about 80°, such as from about 50° to about 70°, such as from about 55 ° to about 67.5 °.

18. The embossing roll of claim 1 , wherein the at least two steps cover a portion of the at least one sidewall in a machine-direction.

19. The embossing roll of claim 1 , wherein a cross machine direction of the at least one sidewall is substantially free of the at least two steps.

20. The embossing roll of claim 1 , wherein the surface of the embossing roll includes a pattern of embossing protuberances.

21. The embossing roll of claim 1 , wherein the surface of the embossing roll includes from about 5 embossing protuberances to about 80,000 embossing protuberances on average per 100 cm2of surface area, such as from about 100 embossing protuberances to about 20,000 embossing protuberances on average per 100 cm2of surface area, such as from about 300 embossing protuberances to about 10,000 embossing protuberances on average per 100 cm2of surface area.

22. The embossing roll of claim 1 , wherein the embossing protuberances are microembossments.

23. The embossing roll of claim 1 , wherein the embossing protuberances form spaced apart rows of line structures.

24. The embossing roll of claims 22-23, wherein the embossing protuberances are in a continuous pattern.

25. The embossing roll of claims 22-23, wherein the embossing protuberances are in a non-continuous pattern.

26. A method of embossing a tissue product comprising: feeding a tissue ply through a nip formed between the embossing roll as defined in any of claims 1-35 and a counter roll in order to emboss the tissue ply according to a pattern of embossing protuberances located on the surface of the embossing roll.

27. The method as defined in claim 26, wherein the process produces a single ply tissue product.

28. The method as defined in claim 26, wherein the embossed tissue ply is attached to one or more tissue ply for producing a multi-ply tissue product.

29. The method as defined in any of claims 26-28, wherein the embossed tissue ply increases in caliper by at least about 10%, such as by at least about 15%, such as by at least about 20%, such as by at least about 25%, such as by at least about 30%, such as by at least about 35%, such as by at least about 40%, such as by at least about 45%, such as by at least about 50%.

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